1. Field of the Invention
The invention relates to a method and a device for determining a steering angle offset.
2. Description of the Related Art
The steering angle sensors used in a vehicle are subject to a certain tolerance when being installed in the vehicle, i.e., their zero position is not exactly adjusted. At high driving speeds, however, even a small deviation of the steering angle sensor can lead to great deviations of the calculated results if the steering angle measured is used, e.g. in vehicle dynamics algorithms within an electronic stability program or in a chassis control system; therefore the error in respect of the zero position has to be determined and taken into account in the calculation.
This can be done by means of a learning algorithm while driving. Usually it is assumed that, on average, the driver drives in a straight line, i.e. the average steering angle should be zero. As a rule, a long-term average is calculated from the steering angles measured in order to determine the deviation from the exact zero position.
This simple method has the drawback, in particular, that the above-assumption is not true in many cases, e.g. if a vehicle is moved regularly between a person's home and workplace and is always turned around in the same direction at the end points while the route chosen for the outward journey and the journey back is always the same, which results in an average steering angle value of 360° in total.